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IQs in the developed world seem to have started to substantially decline with no viable convenient explanation. Maybe what's happening is that IQ has been decl

by Joeri 8y ago

IQs in the developed world seem to have started to substantially decline with no viable convenient explanation. Maybe what's happening is that IQ has been declining for a longer time, but the gains in health and nutrition were offsetting the effect. An interesting variable to compare to is life expectancy, which is a proxy for health. Its growth in western countries has been slowing and in the US it has even started declining. Studies have shown a link between IQ and life expectancy. Those studies generally looked towards a reason why higher IQ would lead to higher life expectancy, but perhaps the causation is reverse.

AstralStorm 8y ago
We do not even have good enough data to support IQ results in a single generation related to this... (there are problems when checking across cultures) Additionally, the tests were modified over time. Is the reaction test the same? Was it checked for reproducibility? Has an alternative hypothesis of slower muscle speed been excluded? So, drawing any conclusion from these numbers is very, very risky, even riskier over time - unless you somehow invent time travel and give Victorian era people the exact same test we give people now. Remember, IQ tests are graded across average in a generation...
- TangoTrotFox 8y ago
  One standard measurement of IQ is the Stanford-Binet exam. It's been around since 1916 with extensive concern given to consistency in the 5 updates it has received over the century. And that consistency is determined through thousands of trials with demographically representative samples to avoid predictable issues like a self selection bias in testing. But like you mention the tricky part is that IQ is measured across an average in a generation. The mean is normalized to 100 with a standard deviation of about 15 points. An IQ of 115 does not mean you 'scored' 115 in a vacuum, it means you performed better than 84% of people. The idea that IQ would substantially increase or decrease for an entire population over very short periods of time (thus changing the meaning, in a vacuum, of e.g. 115 IQ over short periods of time time) was surprising, and that's precisely what the Flynn Effect [1] is. However that change is precisely measurable and enables researchers to produce comparable values between generations. [1] - https://en.wikipedia.org/wiki/Flynn_effect https://en.wikipedia.org/wiki/Flynn_effect

by Joeri 8y ago

AstralStorm 8y ago

We do not even have good enough data to support IQ results in a single generation related to this... (there are problems when checking across cultures) Additionally, the tests were modified over time. Is the reaction test the same? Was it checked for reproducibility? Has an alternative hypothesis of slower muscle speed been excluded? So, drawing any conclusion from these numbers is very, very risky, even riskier over time - unless you somehow invent time travel and give Victorian era people the exact same test we give people now. Remember, IQ tests are graded across average in a generation...

TangoTrotFox 8y ago
One standard measurement of IQ is the Stanford-Binet exam. It's been around since 1916 with extensive concern given to consistency in the 5 updates it has received over the century. And that consistency is determined through thousands of trials with demographically representative samples to avoid predictable issues like a self selection bias in testing. But like you mention the tricky part is that IQ is measured across an average in a generation. The mean is normalized to 100 with a standard deviation of about 15 points. An IQ of 115 does not mean you 'scored' 115 in a vacuum, it means you performed better than 84% of people. The idea that IQ would substantially increase or decrease for an entire population over very short periods of time (thus changing the meaning, in a vacuum, of e.g. 115 IQ over short periods of time time) was surprising, and that's precisely what the Flynn Effect [1] is. However that change is precisely measurable and enables researchers to produce comparable values between generations. [1] - https://en.wikipedia.org/wiki/Flynn_effect https://en.wikipedia.org/wiki/Flynn_effect